343results about How to "Decreased fluorescence intensity" patented technology

This invention relates to oligonucleotides comprising a molecular switch which may exist in an “open” or “closed” position. The molecular switch portion of the probe is particularly sensitive to the identity of sequences complementary to the molecular switch. Oligonucleotides containing a molecular switch are applicable to all kinds of hybridization processes. Due to the sensitivity of the switch domain of the oligonucleotide, probes containing a molecular switch are particularly useful in the identification of single point mismatches. More specifically, a portion, but not all, of the oligonucleotide becomes unbound from a mismatched target. The invention further relates to methods of using said oligonucleotides for research reagents, and clinical diagnostics. An exemplary oligonucleotide comprises a first hybridizable domain, a second bridging block domain, and a third binding domain.

The invention discloses a diamond-based NV ^‑ A nanoscale three-dimensional magnetic resonance molecular imaging device for color centers, comprising: a glass base; a laser, arranged inside the glass base, for emitting laser light to the outside; containing NV ^‑ The diamond with the color center is arranged on the upper surface of the glass base, and the laser emitted by the laser is directly irradiated to the diamond; the microwave pulser is used to input microwave pulses to the diamond; the microscope objective lens is used to make the NV of the diamond ^‑ Fluorescence from the color center is emitted outward through the microscope objective; a monochromatic filter for filtering the NV of the diamond ^‑ Fluorescence from color centers; nanoconvex lenses that filter the NV of the diamond ^‑ The fluorescence emitted by the color center is further concentrated; the distributed optical imaging lens is used to realize the imaging function; the packaging device is used to realize the functions of stable temperature, electromagnetic shielding and isolation protection.

Nanoparticle-amphiphilic polymer complexes for nucleic acid delivery and real-time imaging.

The invention relates to a preparation method of carbon quantum dots based on amino acid and an application of carbon quantum dots in direct detection of metal ion concentration. The method comprises the following specific steps: uniformly mixing amino acid and distilled water, rapidly adding the uniformly-mixed solution (amino acid is dissolved in distilled water) into a round-bottom flask filled with phosphoric pentoxide, rapidly plugging the bottleneck so as to obtain water-soluble carbon quantum dots, and applying the prepared carbon quantum dots in detection of metal ion concentration by a fluorescence quenching method. The synthetic method provided by the invention has a simple process, and reagents and raw materials are green and nontoxic. The prepared carbon quantum dots have characteristics of high quantum yield, strong light stability, good water-solubility and the like. Based on the quantum dots, a simple, rapid and sensitive method for metal ion quantitative detection can be established.

The invention discloses a rare earth organic framework material for iron ion fluorescence detection and a preparation method thereof. Methoxyl functional group-containing linear dicarboxylic acid (L-OCH3) is used as an organic raw material, a hydrothermal reaction is performed on the organic raw material and metal rare earth salt, and in the reaction process, an in-situ reaction is performed on methoxyl functional groups of an organic ligand to produce hydroxyl functional groups and the rare earth organic framework material is obtained. After adoption of the hydrothermal preparation method, the method is simple and the yield is high; the prepared rare earth organic framework material can be used as a fluorescent probe and interacts with iron ions, so that fluorescence of the organic ligandis quenched and new fluorescence generating a Ln2 (L-OH) 3-Fe<3+> compound is enhanced, and the intensity ratio between two peaks has a relatively good linear relationship with the concentration of the iron ions; the rare earth organic framework material can be applied to ratio detection of the iron ions.

A chemical preparation method for a CdTe quantum dot fluorescent probe for detecting a trace amount of paraquat comprises the step of modifying thioglycollic acid on the surface of the CdTe quantum dot fluorescent probe emitting a red emission spectrum band so as to enable the CdTe quantum dot fluorescent probe is provided with carboxyl functional groups on the surface. The preparation process comprises the following two specific steps: firstly, preparing a NaHTe solution; then, synthesizing CdTe quantum dots of which the surfaces are modified with thioglycollic acid, and adjusting the pH value to be 10-12 with KOH, so as to obtain the CdTe quantum dot fluorescent probe. According to the invention, carboxyl with negative charge on the surfaces of the CdTe quantum dots and target paraquat molecules with positive charge have the electrostatic interaction through the positive charge and negative charge, when the CdTe quantum dots and the paraquat approach to each other in space, the red spectrum band emitted by the CdTe quantum dot fluorescent probe can be absorbed by green target analyte paraquat modules through the fluorescence resonance energy transfer principle, and the detection of a trace amount of paraquat can be implemented through the utilization of the variation of the CdTe quantum dot fluorescence intensity.

A method for complexing AHF in a dispersed medium, includes: a) providing an AHF protein, b) altering the conformational state of the AHF protein to expose hydrophobic domains therein, c) binding a stabilizer to the exposed hydrophobic domains, and d) at least partially reversing the alteration to associate at least a portion of the protein with the stabilizer. A pharmaceutically effective stabilized AHF dosage wherein above about 0.5%, preferably above about 3%, and more preferably above about 25%, of the AHF molecule is associated with a stabilizer is also disclosed.

The invention discloses a carbon quantum dot sensor with copper ion and cysteine recognition functions, a preparation method and application thereof. The carbon quantum dot sensor is prepared by the following steps: taking citric acid and ethylene diamine as raw materials, adopting a microwave method to synthesize a carbon quantum dot containing carboxyl on the surface, then taking 2-bromoethylamine and 1,4,8,11-tetraazacyclotetradecane as surface functionalizing reagents, and utilizing a surface grafting technology. The carbon quantum dot sensor is good in dispersity in water, and can be used for double-selectivity fluorescence detection to the copper ion and cysteine. Compared with the existing detection technology, the carbon quantum dot sensor disclosed by the invention can detect trace of copper ion and cysteine in a pure water medium with high sensitivity and high selectivity, is simple in synthetic route, convenient to use, and suitable for large-scale synthesis and actual application in production, and has the enormous application prospect in the fields such as biology and environment detection.

The invention discloses an amphiphilic lipid-droplet fluorescent probe with super-high selectivity. The amphiphilic lipid-droplet fluorescent probe with super-high selectivity is characterized in that chemical name of the probe is 1-(3'-(7'-nitrobenzofurazan-4'-)aminopropyl)-2,3,3-trimethylindole bromine, NII for short; and the general chemical formula is as shown in the formula (I). The invention also discloses application of the probe in specifically marking or displaying the form and distribution of lipid droplets in living cells or tissues. Experiments confirm that the probe of the invention is a brand-new probe, has a wide range of application, has good single- and two-photon photostability, fast staining speed and low cytotoxicity, can specifically image lipid droplets in living cells and has a wide application prospect.

The invention discloses a cell lipid droplet specific-labeling fluorescent probe. The fluorescent probe has a chemical name of 1-(3'-(7'-nitrobenzofuran-4'-)aminopropyl)-4-methylpyridine bromide and has a general chemical formula shown in the formula (I). The invention also discloses a use of the fluorescent probe in specific labeling or display of a lipid droplet form and distribution in living cells. An experiment result shows that the cell lipid droplet specific-labeling fluorescent probe has the characteristics of very high selectivity, background noise-free imaging, two-photon performances, very good light stability, fast dyeing ability, no use of washing and low cytotoxicity and has a great application prospect.

The invention discloses star-shaped tetraaryl ethylene compounds. In the invention, the star-shaped tetraaryl ethylene compounds with rigid frameworks are synthesized through molecular design, each compound molecule contains one or more tetraaryl ethylene groups, and the compounds have special luminescent properties, namely the properties that the compounds almost have no fluorescence in dilute solution and fluorescence is greatly enhanced in an aggregation state or solid state. The invention also discloses a preparation method for the star-shaped tetraaryl ethylene compounds. The compounds have higher decomposition temperature and high thermal stability, and can be used as organic fluorescent materials which are applied to devices. The structural general formula of the compounds is shownin the specification, wherein X and Y are positive integers and the sum of X and Y is equal to 6.

The invention discloses a rhodamine B targeted lysosome pH fluorescent probe with a cysteine ethyl ester structure, wherein the rhodamine B targeted lysosome pH fluorescent probe has the structure as shown in a formula (I). Meanwhile, the invention discloses an application of the probe as a living cell lysosome pH fluorescent probe. Experiments show that the probe provided by the invention does not generate fluorescence under the neutral and alkaline conditions, the fluorescence intensity is rapidly enhanced along with the reduction of the pH value of the solution, is up to the maximum value when the pH value is about 4.0 and is enhanced by about 150 times when the pH value ranges from 7.51 to 3.53, and the probe has favorable antijamming capability and reversibility in the presence of various metal ions. An intracellular colocalization experiment and an interlysosome pH regulation experiment prove that the probe can specially mark a lysosome and sensitively monitor the small change of the interlysosome pH value. A cell survival rate experiment shows that the probe is nontoxic to cells, which indicates that the probe disclosed by the invention has an important application value in the aspects of imaging the cells and monitoring the change of the interlysosome pH value.

The invention relates to a fluorescent quantum dot/nano-metal particle conjugate and a preparation method thereof, a composition and an elisa kit containing the conjugate and an application of the conjugate in detecting target objects especially in detecting metal ions.

The invention discloses an indolizine-rhodamine hydrazide derivative type Cu<2+> ratiometric fluorescent probe. The probe is indolizine substituted rhodamine hydrazide, and the chemical formula of the probe is as shown in formula (1). The fluorescent probe has unique fluorescent selectivity to Cu<2+> in an ethanol solution and is high in sensitivity, high in resistance to interference of other ions and promising in application prospect.

The invention provides a fluorescent detection method for quantitatively detecting ferric ions on the basis of a coumarin derivative (molecular formula: C14H5NO3), and the coumarin derivative 7-lignocaine coumarin-4-formaldehyde is synthesized according to documents. The method comprises the steps: coordinating Fe<3+> and two carbonyls in the 7-lignocaine coumarin-4-formaldehyde structure in a HEPES buffer solution in a pH value of 7.0, and detecting the ferric ions through the fluorescence quenching. The detection method is high in sensitivity and selectivity for the display of the ferric ions, the detection reagent is cheap, the detection process is simple, sensitive and rapid, and the detection result is accurate. In addition, a confocal fluorescence image further proves that a probe can be used for recognizing the Fe<3+> in a living cell.

Disclosed are fluorescent substance-containing silica nanoparticles containing a fluorescent substance therein featured in that the surface of the silica nanoparticles is coated with a material having a bulk refractive index of from 1.60 to 4.00. The invention can provide fluorescent substance-containing silica nanoparticles excellent in long term storage stability and a biosubstance labeling agent employing the same.

The invention discloses an in imidazo[1,5-a]pyridine-rhodamine salicylaldehyde copper ion ratio fluorescence probe and an application thereof. The probe is imidazo[1,5-a]pyridine substituted rhodamine salicylaldehyde, and the chemical structural formula of the probe is represented by formula (1). The fluorescence probe has unique fluorescence selectivity and high sensitivity on Cu<2+> in an ethanol solution, has strong resistance to interference of other ions, and has great application prospect.

The invention provides a benzimidazole quinoline derivative, a preparation method and application in copper ion detection, and particularly relates to a 2-(4-N,N-bis-substituted styryl)-8-1H-benzimidazole) quinoline derivative. Particularly, 2-aminobenzoic acid is used for preparing 2-methylquinoline-8-carboxylic acid, then the 2-methylquinoline-8-carboxylic acid and o-phenylenediamine are subjected to condensation to obtain 2-methyl-8-(2-benzimidazolyl) quinoline, the 2-methyl-8-(2-benzimidazolyl) quinoline and N,N-bis-substituted benzaldehyde are subjected to condensation to obtain the benzimidazole quinoline derivative. A probe has the good complexation with copper ions, when the copper ions exist, derivation of the solution is observed with naked eyes, and the solution is changed from yellow to purple, absorption at the 418 nm position on an ultraviolet visible absorption spectrum is weakened, and a novel absorption peak appears at the 550 nm and gradually increases when the concentration of the copper ions is increased; the benzimidazole quinoline derivative can be used for real-time and rapid measurement of complex samples and can also be used for semiquantitative detection of micro/trace Cu2+ of environment samples from different sources.

The invention relates to a method for detecting hyaluronic acid in human serum, body fluid or tissue homogenate by a radioimmunoassay method. By a method of using solid phase-coated and europium-marked hyaluronic acid binding protein (HABP-Eu<3+>), reagents such as a first antibody, a second antibody and the like are not needed, a sample is easy to add, reaction is quick, the reagents have long shelf life and are environmental-friendly, europium is stably combined with HABP, storage time can be more than 12 months, and radioactive pollution is avoided.

The invention discloses polymer nanoparticles capable of detecting hypochlorous acid and copper ions. The polymer nanoparticles are novel polymer nanoparticles prepared by taking a polyethylene glycol monomethyl ether chain transfer agent, styrene, 2-aminoethylmethacrylate hydrochloride, rhodamine B isothiocyanate and a 9,9-dioctyl polyfluorene-benzothiadiazole alternate copolymer as raw materials. The polymer nanoparticles can realize high-sensitivity ratio fluorescence detection on the hypochlorous acid and the copper ions in a pure water solution. Compared with an existing fluorescence detection technology, the prepared polymer nanoparticles have a double-ratio detection function and good biocompatibility; a synthetic route is simple and a detection method is simple and convenient; the polymer nanoparticles are applicable to amplified synthesis and actual production application, and have a great application prospect in the technical fields including analytical chemistry, life science, environmental science and the like.

The invention discloses a method of utilizing an aptamer molecular switch to detect aflatoxin B1. At first, protection of an aptamer is claimed, and the sequence of the aptamer is represented by the sequence 1 in the sequence table. Then protection of a probe is claim. The probe is obtained by labeling a fluorescent group (FAM) on the 5' terminal of a single chain DNA molecule and labeling a quenching group (BHQ1) on the 3' terminal of the single chain DNA molecule. Protection of a method for detecting aflatoxin B1 is also claimed. The method comprises a step of co-incubating any one of abovementioned probes with a sample to be tested, and if the fluorescent strength is reduced after co-incubation, the sample contains aflatoxin B1. The method has the advantages that aptamer is taken as an affinity ligand and is used to detect aflatoxin B1, the advantages of aptamer can be fully exerted; the provided aptamer molecular switch can generate respond of fluorescence reduction, and the rapid and sensitive detection of aflatoxin B1 is realized therefore.